Protecting the foundation from moisture. Reliable waterproofing of the foundation with your own hands Protecting the foundation from rain

Despite the fact that modern concretes are highly durable, they remain susceptible to various types corrosion. In most cases, this is the impact of aggressive chemical media And groundwater contaminated with acids and alkalis.

Also, do not forget about acid rain, which often falls in industrial areas. It is also slowly degraded by exposure to sulfates and phosphates, chlorides and other strong electrolytes.

If the foundation is built above the freezing zone, then it is also subject to strong pressure from frozen soil, uneven displacement of layers occurs and the base is deformed.

Types of concrete corrosion

• First view. Destruction of concrete occurs due to exposure to various aggressive media contained in groundwater. Due to corrosion of the upper surface of the foundation, slow dissolution occurs cement mortar. Also, groundwater may contain bicarbonate, which is soluble in water, but is highly alkaline and has a negative effect on concrete sand. If the influence of groundwater occurs in winter near the border of the freezing zone, then there is practically no chance of saving the foundation.
• Another type of corrosion occurs chemical reactions metabolism, in which the filling of the foundation slowly dissolves, as well as the destruction of the reinforcing layer. Therefore, it is strictly forbidden to add machine oil or various saturated fats to them when pouring concrete using concrete mixers.
• The most dangerous is the third type of corrosion. It occurs in the process of replacing concrete salts with metabolic products, for example, sea ​​water. In such cases, mechanical expansion of concrete pores occurs, destruction of the load-bearing layers and filling with hydrates. In most cases, this is a classic stage of destruction due to sulfates and carbonates, and the rate of concrete corrosion depends on its porosity, grade and permeability.

If we take into account all possible types of concrete deformation, then it immediately becomes clear that the key medium due to which the destruction of the foundation occurs is groundwater and rainwater.

Therefore, the main way to protect concrete from exposure to aggressive environments is high-quality waterproofing.

It is also necessary to initially build a foundation with a sole below the boundary freezing zone.

Protection of foundations from the effects of aggressive groundwater

As a rule, the impact on the foundation is not so much superficial as it is complex.

After all, there are also internal moments that also lead to destruction load-bearing structures. This is, for example, natural rusting of metal fittings.

If water is allowed to penetrate into the reinforcement layer, then it is no longer possible to stop the process of internal destruction. The resulting iron oxide reacts with the components of concrete, replaces them and forms huge open spaces.

Methods for neutralizing corrosion of metal reinforcement layer

1. When constructing the base, all reinforcing bars are completely filled with concrete, and any possible contact with the environment is eliminated;
2. Adhere to the rules for laying reinforcement, because it must be located at a distance of at least 2.5 cm from the surface;
3. When pouring concrete mortar, eliminate air pockets and use only fine gravel;
4. If the reinforcement is also installed in the soil freezing zone, then add special compounds and minerals that block the process of metal corrosion. They also coat the metal itself with a thick layer of oxide and create an additional barrier of protection.

It is also recommended to carefully familiarize yourself with the composition of cement, especially its quantitative components. As a rule, it is prohibited to allow the concentration of calcium chloride to exceed 2% of the total mass of cement.

Although it is an important mineral component, it reacts with carbon dioxide, forming chalk. And over time, under the influence of even weak acids, it dissolves. Accordingly, destruction of the reinforcement is inevitable, because liquid calcium chloride is very active.

If the concentration of calcium chloride is allowed to exceed, then only highly specialized specialists can stop the destruction of the foundation, and the financial costs will be enormous.

Secondary protection of the foundation from corrosive factors

Such protection involves applying special protective paints or varnishes to the outer surface of the base.

As a rule, impregnation is done here to the maximum possible depth, but there are many factors that influence stopping the process of concrete deformation. First of all, this:

1. Anti-corrosion coating does not always guarantee stopping the process;
2. Without special inhibitors in the concrete, the external coating will not always be effective enough;
3. The time factor plays an important role, because internal corrosion of metal cannot be stopped by coatings;
4. The effectiveness of impregnation depends on the composition and consistency, so it is recommended to use a liquid mixture for maximum penetration into the material. On the other hand, the consumption of liquid mixtures is huge, and viscous compounds are easy to apply, but penetration is minimal.

Features of protecting the base of the foundation from corrosion in the freezing zone

Considering that in the freezing zone the bud is especially susceptible harmful effects, then you need to choose the right protective substances and compositions.

First of all, here you need to do external impregnation with frost-resistant anti-corrosion compounds. They are produced on the basis of minerals and epoxy resins.

The depth of concrete impregnation at the freezing depth must be at least 10 cm, and the reinforcement must be located at a distance of at least 5 cm from the outer surface of the foundation.

They also practice coating reinforcing bars with polymer resins, and mineral ingredients are added to the concrete that can withstand the effects of low-temperature groundwater.

Principles of protection

As a rule, the most severe destruction of concrete occurs through the influence of three key factors at once: moisture, electrolytes and frost. Therefore, concrete in the soil freezing zone is subject to severe destruction; on such horizons it is necessary to use frost-resistant and moisture-resistant concrete mixtures.

Additional anti-corrosion treatment of the sole is also carried out, subject to its availability. Columnar structures are not treated with anti-corrosion compounds; here the problem can only be solved by choice correct concrete and the presence of a high-quality waterproofing layer.

Thus, concrete in this zone is protected by two methods at once: internal structural changes in the characteristics of concrete and external treatment. Only a combination of these methods can save the foundation from destruction.

In specialized construction stores you can always buy organic and mineral additives that increase the strength and durability of concrete before exposure to aggressive environments.

It is recommended to carry out secondary treatment with expensive hydrophobic compounds, as well as polymer liquid mixtures. The main purpose of such protection is to fill the air formations and pores of concrete with compounds that are resistant to external aggressive environments.

Also, in the process of applying the compositions, a durable protective film is formed on the concrete surface itself. The coating is used at the stage of laying the foundation or during its repair.

What is internal foundation protection

It is done at the stage of laying the future foundation. As a rule, the essence of protection is right choice concrete mixture, as well as increasing its characteristics by adding special ingredients.

Chemical modulators are now popular, and it is recommended to purchase and use them carefully. For example, lignosulfonate is used to protect concrete from groundwater with high sulfate content.

Also, the destruction of the cement base can be stopped with the help of amorphous silica. This is ordinary modified sand, produced chemical methods and is characterized by high hygroscopicity.

Silica in concrete replaces calcium oxide and forms silicates that are resistant to acids and alkalis. And the use of electrolytic additives accelerates the hardening process of concrete and its gaining of grade strength, and neutralizes oxides.

The most popular and cheapest are soda ash, potash and alkali metal bicarbonates.

In the construction of foundations, where it is necessary to obtain high structural strength below the soil freezing depth, chemical additives with a plasticizing effect are actively used.

Mylonaft improves waterproofing properties and frost resistance, and sulfite-yeast mash promotes rapid hardening. Organosilicon solution GKZh-94 increases frost resistance three times at once.

External treatment of foundations with anti-corrosion compounds

The following materials and compositions are actively used here:

1. Aerosol thin coatings with varnish or paint.
2. Mastic coatings.
3. Pasting films.
4. Polymer cladding.
5. Liquid impregnation.
6. Hydrophobization method.
7. Use of biocidal compounds.

Paint and varnish coatings protect against exposure to liquid and gaseous media. Such a film only protects concrete from external factors, it also serves as a barrier to microorganisms and rodents, and also neutralizes the effects of moisture.

Mastics based on epoxy resins and bitumen are now very popular. Apply the compositions with a brush or spray; drying time depends on the composition and temperature environment, the depth of penetration into concrete depends on its structure and can be up to 10 cm or more.

Pasting films are recommended for use in soils with a high groundwater content, as well as near industrial enterprises with high volumes of aggressive wastewater. For example, columnar foundations immersed in water are additionally covered with polyisobutylene films and plates.

It is also highly efficient polyethylene film and rolled petroleum bitumen (roofing felt).

How to increase the waterproofing performance of a foundation

Any existing methods protecting concrete from corrosive destruction will not be effective if the surface waterproofing is poor. Therefore, you must first increase the waterproofing characteristics of the foundation, and for this purpose special water repellents are used:

• Powders: bentonite, polymer emulsion.
• Salts: metal stearates and oleates.
• Plasticizers - resins.
• Hardening activators - chlorides

Thus, protecting the concrete foundation is especially important in terms of ensuring the reliability and safety of the entire structure as a whole. Waterproofing is applied in a thick layer at a height of at least 15 cm from the sole and rises to the top edge of the ground.

Roofing felt, pine mastic and slaked lime are excellent for such purposes. The entire finished coating is additionally impregnated with antiseptics.

Even at the construction stage, it is necessary to think about how to ensure protection from ground and melt water. To do this, it is necessary to treat the foundation with special waterproofing materials. If such a procedure is neglected, then the reliability and durability of the foundation and the entire house will be at risk. Providing protection from moisture is necessary for any type of foundation.

After the foundation has gained the necessary strength, it needs to be treated with bitumen mastic on top and roofing felt laid on it.

Waterproofing can be done in a horizontal or vertical plane. For horizontal waterproofing, roll materials are used, for example, roofing felt, which is laid at the base of the foundation and the place where it joins the walls of the house. When performing vertical work, it is subjected to processing with materials such as bitumen or the like. Can be used liquid glass, which is quite durable, or adhesive insulating materials, presented in a wide range on the modern construction market. Each of the available modern construction materials has its advantages and disadvantages. Choose best option for your project, only you can do it yourself, based on the information about each method.

Horizontal waterproofing

Horizontal for waterproofing is optimal for strip or monolithic slab foundations. When building a foundation, a clay or sand cushion is first laid, the first layer of concrete is poured on top, and after 10-12 days, when the concrete has hardened, its surface is covered with bitumen mastic, and roofing felt is laid on it.

Then the surface of the roofing material is again treated with bitumen mastic, and the roll material is again laid on it. On top of the second layer of roofing material, another one is made concrete screed 5-8 cm thick. After this, they begin directly to build the foundation. Additionally, you can use vertical methods of moisture protection, this will increase its effectiveness.

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Vertical waterproofing

Vertical waterproofing is the direct treatment of foundation walls with various compounds.

For this you can use various materials: bitumen, roofing felt, plaster, liquid rubber, penetrating compounds. Each of these processing options has its own advantages and disadvantages, which will be discussed below.

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Treating the foundation with bitumen

The use of bitumen is one of the most common methods of treating foundations. Its entire surface is treated with bitumen mastic, which prevents moisture from penetrating into cracks and crevices. The main advantages of this method of waterproofing are its low cost and simplicity. Bitumen is sold in solid form. You will need to melt it and apply it in a liquid state to the surface in several layers (2-4).

It is advisable to melt bitumen in small quantities. In this case, it will not have time to harden while you apply it. Otherwise, when re-melted, the properties of the bitumen will deteriorate. In addition, to improve the characteristics of the material, it is recommended to add a small amount of waste oil to hot bitumen. An alternative to using bitumen is the use of ready-made mastics based on it, which do not require heating.

In addition to such advantages as low price and availability, it also has its disadvantages. These include the short service life of such a coating (re-treatment may be required after 5 years). In addition, waterproofing in this way requires a certain amount of time, and the result does not provide full protection from exposure to water.

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Processing of roll materials

For vertical waterproofing, you can also use rolled materials, for example, roofing felt. The process of laying the material is similar to roofing. The surface of the foundation of the house is covered with mastic, onto which roofing material is applied, preheated with a gasoline burner. The seams of the material are overlapped. The gap should be 10-15 cm.

After this, they need to be treated with a burner. As an alternative to the burner, you can use special adhesives, but in this case the strength will be reduced. The main advantages of this method are similar to bitumen processing. This method is inexpensive, and at the same time the service life of such waterproofing is very long (up to 50 years). However, it is impossible to install roofing felt alone; you will have to involve assistants or craftsmen.

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Waterproofing with plaster

This is one of the simplest and the most convenient ways processing. It simultaneously serves to level the surface of the house and waterproof it. To implement this method, special components are added to the plastering mixture to provide water protection. Using a spatula, the resulting solution is applied to the foundation. Before applying the plaster, it is recommended to install a plaster mesh, which will help the solution adhere to the surface being treated. However, this method does not provide high water protection and is short-lived (up to 15 years). In addition, cracks may appear in the surface of the plaster. However, the advantages of this method of waterproofing make it quite popular. These advantages include: low cost of materials, ease of work, the ability to carry out all work in the most short term.

Instructions

Wetting the foundation can lead to its complete destruction. The degree of danger depends on the hydrogeological conditions of the region in which the building is built: groundwater level, soil density, freezing depth, and others. The main factor destroying concrete base buildings - hydrodynamic expansion of moisture accumulated in the foundation during freezing. Not less problems Erosion can also bring home owners, because high humidity is always accompanied by the appearance of microorganisms that slowly but surely destroy the very structure of concrete from the inside. If the soil density is low, the accumulation of moisture in the area of ​​the foundation can lead to uneven shrinkage of the soil, due to which the foundation will receive additional load and may simply burst. Based on the foregoing, it can be unequivocally stated that the protection of the foundation from moisture in all cases must be ensured individual approach.

The main method of protecting reinforced concrete foundations from oversaturation with moisture is waterproofing. By its type, it can be moisture-proof, used when the foundation depth is less than one meter, and pressure water-resistant, which is used for structures laid to a considerable depth. According to the principle of application waterproofing materials there are also different types. Tape or roll insulation is a wide strip of water-repellent material that is attached to the outer surface of the foundation. Coating insulation is a hydrophobic paste or mastic that is applied to the surface concrete structure. Penetrating waterproofing closes the pores in concrete and forms a thin film on the surface, which together prevents the penetration and accumulation of moisture. The use of such materials solves the problem of foundation wetting in most cases.

At high level groundwater and heavy rainfall, it is necessary to think about the design of a drainage system. It is an intricate network of pipes through which excess moisture is removed from the house and discharged into the soil or into a specially prepared well. Protecting the foundation from water using this method shows very good results in practice, but is often associated with serious material costs. Equipping drainage system only in exceptional cases and, as a rule, after complex geological research.

The source of moisture in the foundation area is not only groundwater, but also precipitation. To avoid leakage of rain or melt water under the foundation, it is necessary to build a blind area around the entire perimeter of the building. This is a cement or concrete screed, from 60 centimeters to several meters wide, forming a monolithic structure with the foundation. The main function of the blind area is to protect the foundation and the soil around it from moisture seepage, dumping it onto the soil at a safe distance. Often, this measure alone is enough to keep the foundation dry throughout the year.

How to protect concrete from moisture? In this article we are going to look at several popular solutions that are applicable both for waterproofing foundations and basements, and for protecting main walls from precipitation and seasonal humidity fluctuations.

Our goal is to give the concrete hydrophobic properties.

Classification

All waterproofing materials are divided into three main categories.

Useful: roll and coating materials are usually applied on the side of the foundation or enclosing structure on which there is excess static water pressure. Otherwise, there is always a risk of peeling off the protective layer and compromising its integrity. Penetrating waterproofing does not have this limitation.

Obviously, we are most interested in the last category of waterproofing. It is with her that we will get to know each other better.

Possible solutions

Ironing

The simplest and cheapest surface treatment (applying cement laitance to it). Cement penetrates into pores and microcracks, completely or partially clogging them. Of course, such waterproofing is not enough for the foundation; but the ironwork cement plaster facade will significantly reduce water absorption.

Liquid glass

If you add to cement-sand mortar sodium liquid glass (aqueous solution of Na2O(SiO2)) in a ratio of approximately 1:10, you will get moisture-resistant concrete with a very short (no more than half an hour) setting period. This recipe is often used to seal sewer and water wells, block foundations, and cracks in basement floors.

The photo shows domestically produced sodium liquid glass.

Treatment with liquid glass is quite capable of reliably waterproofing the surface of the finished reinforced concrete product. Doing this work with your own hands is more than simple: the material diluted with water in a ratio of 1:1 is applied to the concrete with a brush, roller or spray.

Hint: undiluted liquid glass, applied in one layer, penetrates concrete by an average of 2 millimeters. If the processing is carried out aqueous solution and in several steps, the depth of impregnation will increase to 15-20 mm.

Water repellents

How to treat aerated concrete against moisture if it is used to construct the external walls of a residential building?

In this case, silicone-based hydrophobic primers will come to the rescue. The instructions for their use are also extremely simple: the composition, ready for use or diluted with water in the concentration specified by the manufacturer, is applied to the surface of the facade in two or three layers without preliminary drying.

Protecting aerated concrete from moisture using a water-repellent solution solves several problems at once.

Let us clarify: silicone-based water repellents are intended not only for aerated concrete. They can process all porous materials: heavy concrete, limestone, plaster, etc.

The composition is applied to a dry base. A concrete moisture meter - a simple electrical device that measures resistivity surface area.

The average price of Russian-made water repellents is 150 rubles per kilogram. The only drawback of the solution is the limited adhesive properties of the facade after treatment: it can only be painted after six months.

Crystallizing compounds

Penetron, Crystallisol and their numerous analogues differ from the solutions listed above in their operating principle: simply put, they do not transport material to fill pores through capillaries from the surface, but create it on the spot ().

Chemical additives cause accelerated crystallization of calcium salts (the main component of Portland cement) upon contact with water. The crystals reliably fill the pores of concrete.

What is the result?

• The most obvious result is the impossibility of moisture penetration into the thickness of concrete during external treatment of the structure. If the basement walls are treated with the same Penetron from the inside, groundwater will no longer find its way into the room: the impregnation penetrates 40-60 centimeters into the concrete.
• Of course, you can also forget about efflorescence and mold.. Moisture is necessary for their appearance.
• Frost resistance of concrete increases by an average of 100 cycles. WITH practical side this means an increase in the service life of capital walls by 150-200 years.
• Finally, moisture impregnation for concrete increases its compressive strength: the absence of pores prevents the material from crumbling under load.

It is curious that Penetron and its analogues provide a kind of self-healing waterproofing. Where water begins to penetrate into the concrete through new cracks and pores, the growth of calcium salt crystals immediately resumes. What is especially pleasing is that waterproofing measures can be carried out with damp walls or foundations.

Where do new cracks in concrete structures come from? The main reasons are movements and frost heaving of soils, as well as installation work. When perforating technological holes and openings, shock vibration is destructive to concrete.

What to do?

1. In the first case, the problem is solved by enhanced reinforcement of structures. A foundation connected by reinforcement into a single rigid frame will not deform during any movement of the soil.
2. In the second - using less destructive methods of work. Thus, cutting reinforced concrete with diamond wheels, and cutting reinforcement with a gas cutter or a regular abrasive wheel, is much less destructive than using a jackhammer. Diamond drilling of holes in concrete is much more preferable than using a hammer drill.

Conclusion

As part of a short review, we have listed only a small part possible solutions. As usual, the video in this article will offer the reader Additional information ().

Protecting the basement from moisture is a necessary and primary task when forming the basement of a house. The base is the connecting link between the above-ground structures of a structure and its fundamental underground foundation. The strength of the base largely determines the stability of the entire structure. During the construction process, it provides the necessary surface for the construction of facade walls. In the future, its main function will be protection from penetrating atmospheric and ground moisture.

Meanwhile, the very foot of the house suffers most from dampness and becomes the most vulnerable point in the structure. It takes on the consequences of heavy rains and melting snow, leading to destruction. Therefore, waterproofing the base is necessary; in addition, it requires careful attention to the choice protective equipment, which are able to adequately withstand the aggressive action of water.

Means and methods for protecting the basement of a house from moisture

Basement waterproofing.

When choosing materials for waterproofing the base, it is necessary to take into account that work is carried out in two directions:

• vertical protection, which involves applying a coating to the wall surface;
• horizontal protection - laying waterproofing between the walls of the basement and the foundation.

Horizontal insulation of a house can prevent the penetration of capillary moisture into the above-ground structures of the building. It is implemented using rolled materials. The most common among them are roofing felt and roofing felt. Roofing felt has a cardboard base, so when choosing it you should understand that you cannot count on a long service life.

Modern roofing felt coatings are more effective. They are made of elastomeric bitumen, and the role of the supporting layer is performed by polyester non-woven materials or durable glass fiber.

Vertical is very variable and can be performed different ways waterproofing treatment.

1. Spreading involves the use of bitumen and its analogues. The thick consistency of the material makes it possible to achieve a thick protective layer on the surface of the house. However, this material does not have high strength indicators. It is too unstable to mechanical damage. Innovative Construction Materials, for example, liquid glass, is much more durable and efficient.
2. Protective varnishes and paints are used for painting. The advantages include affordability and simplicity of the application process.
3. The impregnation process is based on the use of liquid polymers and synthetic resins.
4. Pasting allows the use of a wide range of rolled waterproofing materials.

When choosing a product that will help treat the plinth, it is necessary to take into account compatibility with the building material used to construct the plinth.

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Penetrating waterproofing

The advantage of penetrating waterproofing lies in the fact that it is able to penetrate 90 cm into the thickness of concrete. It moves along the same cracks and capillaries through which moisture could move. Having penetrated into the thickness of concrete, the material reacts with the components of concrete.

Penetrating waterproofing fills all the small cavities of the concrete structure of the house, due to which the material gains strength (the strength of concrete increases by 20%). Chemical composition makes it resistant to acids, alkalis and petroleum products, in addition, it is not subject to mechanical stress.

Clean the surface from dust and construction debris. Dilute the dry powder in water, following the instructions on the package, stir the mixture thoroughly until homogeneous. The mixture must be applied to the moistened surface of the concrete structure. Apply the first layer of penetrating waterproofing to the base, and after it has dried, apply the second. Experts recommend waterproofing with penetrating materials using synthetic brushes or a special mortar pump. The basement of a house can only be treated with this type of material at temperatures above zero.

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Rolled adhesive waterproofing

Under roll materials understand bitumen, polymer and synthetic waterproofing. The material is glued to all base structures of the house. Typically, external walls are covered with several layers of waterproofing. If the house is located in an area with big amount groundwater, the number of layers can be increased to five.

Layers of insulation are glued to the outer walls of the basement, overlapping them. This type of insulation is not resistant to damage, therefore, at a distance of 1 cm from the surface of the waterproofing layer, a half-brick brick wall is erected or a reinforced concrete block is installed. The space between the protective wall and the waterproofing is filled with bitumen mastic. Installation work can be carried out at an ambient temperature not lower than 10°C.

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Coating waterproofing

When protecting the surface of the base from moisture, it is worth paying attention to the coating materials that are applied to the internal and external surfaces. If the mastic is applied with outside walls, moisture is prevented from penetrating into the room. There are several types of coating materials: bitumen mastics, cement-polymer waterproofing, polymer-bitumen mastics.

Bitumen-based mastics are the most accessible, but have a short service life. After operation for 5 years under the influence low temperatures the bituminous material is destroyed, and external moisture will penetrate into the room.

Cement-polymer and polymer-bitumen waterproofing is more resistant to frosty conditions. When installing them, it is necessary to ensure protection from mechanical damage. Clean the surface, apply mastic in several layers depending on humidity and dry the structure.

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How to protect a brick plinth from moisture

Performed in several ways:

• lay brickwork pre-treated with waterproof impregnation in the factory;
• use bitumen lubricant applied to the surface in several layers;
• cover with roofing felt;
• apply mortar special penetrating composition.

The latter method is based on the action of the active components of the mixture, which, once they get into wet microcracks or pores, clog them with their own crystallization.